HCC’s Network Time Protocol (NTP) Client module comprises a single task that handles communication with NTP servers.

NTP is used to synchronize clocks on computer systems in packet-switched networks. The NTP client implements mitigation algorithms and authentication. NTP authentication uses keys with the Message Digest algorithm 5 (MD5).

The NTP module is part of HCC’s MISRA-compliant TCP/IP stack and is designed specifically for use with it.


The main features are:

  • Conforms to the HCC Advanced Embedded Framework.
  • Compliant with HCC’s MISRA-compliant TCP/IP stack.
  • Designed for integration with both RTOS and non-RTOS based systems.
  • Compliant with RFC 5905. It supports the the On-Wire Protocol (RFC 5905, Chapter 8).
  • Backward-compatible with RFC 1305.
  • Supports NTP unicast (RFC 1769), NTP broadcast (RFC 2030), and NTP manycast (RFC 4330).
  • Supports the NTP Authentication symmetric key (MD5; RFC 1305, Appendix C).
  • User demo package.

The following NTP algorithms (RFC 5905) are supported:

  • Clock filter algorithm
  • Selection algorithms
  • Cluster algorithms
  • Combine algorithms
  • Clock Discipline Algorithm (CDA)
  • Clock-adjust process